The state of lipid peroxidation and antioxidants following thrombolytic therapy with rt-PA and streptokinase in acute myocardial infarction

The role of reactive oxygen products in myocardial damage caused by ischemia-reperfusion has been established in a number of studies performed in animals models. However, studies showing the development of increased free radicals following effective myocardial reperfusion in humans are scarce. In the present study, both the increase of lipid peroxidation (LPO) following early stage thrombolytic therapy which is the current treatment issue performed after acute myocardial infarct (AMI) and the plasma levels of vitamin E and C (chain braker antioxidants) were investigated parallel to time. Forty patients with AMI who were admitted to hospital within six hours from the beginning of symptoms were included in the study and divided into two groups; group 1 (recombinant tissue-Plasminogen Activator, rt-PA group) and group 2 (streptokinase group). Serial serum specimens were drawn before and 30, 90 minutes and 24 hours after thrombolytic therapy for the investigation of LPO, vitamin E and C levels. Echocardiographic examination was performed on the tenth day to evaluate the functions of the left ventricle. Plasma levels of lipid peroxides (LPO) were found to increase 90 minutes after thrombolytic therapy in each group, while the levels of vitamins E and C showed significant decreases. The difference between the two groups was not significant. Similar to this finding, no significant difference in the ejection fraction values was observed between the groups. Further, no correlation was observed between the ejection fraction and LPO values at the 90th minute which is considered to be the time of successful thrombolysis. In conclusion, the occurrence of a series of biochemical changes confirming an increase in free radical development of peripheral blood was observed. Although the decrease in vitamin E and C levels suggests the need for supplementation of these vitamins along with the thrombolytic therapy, the fact that at least a week is needed for an increase of tissue levels of vitamin E confirms the opinion that the daily prophylactic doses of these vitamins is suitable for the decrease of AMI risk.